Process of obtaining sterol glucosides and sterols from fatty substances



Patented Dec. 17, 1940 UNITED STATES PATENT OFFICE PROCESS OF OBTAINING STEROL GLUCO- SIDES AND STEROLS FROM FATTY SUB- STANCES poration of Indiana N Drawing.

Application October 3, 1938,

Serial N0. 233,030

'1 Claims.

It is the object of our invention to obtain sterols from fatty substances which contain them, including oils and oil sludges, and more especially from soybean oil, cottonseed oil, wheatgerm oil, peanut 011, corn oil, and fish-liver oil.

The invention in this present application is correlated with inventions set forth in two copending applications filed by us in conjunction with Pearl H. Brewer, Serial No. 122,218, filed January 25, 1937, and Serial No. 171,984, filed October 30, 1937, but goes beyond, the inventions set forth in those applications..

According to the process of the present application, fatty substances which contain sterols are brought, in a liquid state, into intimate contact with an adsorbent material (defined hereinafter) which has a high affinity for phosphatides and mucilages, so that it adsorbs those phosphatides and mucilages from those fatty go substances; and with the phosphatides and mucilages so adsorbed there is also adsorbed from the fatty substances a large part of the sterols and practically all of the sterol glucosides which the fatty substances may contain. This adsorption as process thus separates the fatty substances into two fractions-the fraction that is adsorbed and the fraction that is not adsorbed.

When that adsorbent material with the adsorbed material on it is treated with acetone,

30 the acetone extracts the adsorbed sterols and much of the adsorbed sterol glucosides, while leaving on the adsorbent material substantially all the phosphatides and mucilages. This extraction process with acetone thus separates the first 35 fraction into two sub-fractions.

When that acetone extract is subjected to evaporation to drive off the acetone and any water that may be present, there remains an oil in which there is a substantially white precipi- 40 tate if the original fatty substances contained sterol glucosides; and the precipitate, if any, and

The 011 thus obtained is an oil that is rich in sterols, and that is substantially free from phosphatides, mucilages, and sterol glucosides.

The oil that is a filtrate from the adsorbent material, or the combined filtrates if there are 6 several filtrations, is also an oil that contains sterols and that is substantially free from phosphatides, mucilages, and sterol glucosides.

Thus both of these oils, or oil-fractions, are sources of sterols. By our invention we recover the sterols from such phosphatide-free and mucilage-free oil; desirably after obtaining such phosphatide-free and mucilage-free oils by the aforesaid a'dsorption process.

The oil remaining as a residue from the acetone extract in the case of soybean oil may contain sterols to the extent of about 0.5% to 0.75%; whereas the original soybean oil may contain sterols to the extent of about 0.20%, and the filtrate of soybean oil from the adsorption step may contain sterols to the extent of about 0.10%. With cottonseed oil the amounts are somewhat higher. With other oils the percentages vary with the nature of the oil; and of course there is some variation in the same class of oils, even in soybean oil.

In recovering the sterols from these oils, or oil-fractions, we proceed as follows:

First we extract the substantially phosphatidefree and mucilage-free oil or oil-fraction with an organic sterol-dissolving solvent that is substantially immiscible with the oil when cold (0 C. to room temperature). Examples of such solvents are methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, ethylene glycol, and propylene glycol. The extraction may be done by any usual extraction procedure of extracting one liquid with another, either at room temperature or at elevated temperature; for any mixing which occurs at elevated temperature may be made substantially to disappear by cooling, as to room temperature or in a refrigerator.

On standing, with such cooling as may be necessary, the two layers separate because of such lmmiscibility; and may be removed one from the other in any convenient manner, as by a separatory funnel.

The layer of solvent contains the greater part of the sterols, the proportions depending upon the extent to which the extraction is carried; and it may also contain a relatively small amount of the oil because of the impossibility of absolute immiscibility.

The solvent layer is now subjected to evaporation to drive of! the solvent, leaving an oily resi- 55 duewhichcontainssterolsinmuchgreatercom centration than does the original freeoil-Aisuallyinexcessof2.0%inthecaaeof soybeanoiiorcottonseedoil. Thisoilyresidue a subsequent one, are cooled, to room temperature or in a refrigerator, the sterols contained in them are crystallized out to a large extent, usually in a very pure form, often of the order of 98% to over 99%. The crystallization of the sterols is helped by cooling to low temperature. as by refrigeration. The crystals formed are suitably separated, as by filtering or centrifuging.

This crystallizing out of the sterols in this high purity is dependent on the freedom of our oil or oil-fraction from phosphatides and mucilages.

As so far described, it is contemplated that the sterols are obtained without saponification of the oil of the final concentrate, and we prefer that procedure both because of its simplicityand because it does not destroy the oil; although after obtaining our oil concentrate it is possible to use known saponiilcation procedures.

The sterols obtained by our process may be separated into groups or into individual sterols by known processes.

The adsorbent material which we use maybe.

of various types, so long as it has a sufllciently high affinity for phosphatides and mucilages that on intimate contact with the fatty substances it will adsorb those phosphatides and mucilages substantially completely; for along with those phosphatides and mucilages it also adsorbs substantially all the sterol glucosides and much of the sterols of those fatty substances. Any solid inorganic adsorbent material may be used of which'a -gram lot is capable of adsorbing from 200 grams of a crude soybean oil of between 0.06% and 0.08%v phosphorous. content at least enough phosphorous-containing material to re duce the phosphorous content of the oil to onethird of its original value. Among such adsorbent materials are Lloyd's reagent and certain other treated aluminum silicates, precipitated tricalcium phosphate, and some artificial, zeolites; and two excellent adsorbent materials are the silica foam which is described in the copending application of Brewer and Kraybill, Serial No. 121,573, filed January 21, 1937, and the specially prepared sodium aluminum silicates which are described in the co-pending application of Kraybill, Brewer, and Thornton, Serial No. 121,572, filed January 21, 1937. These are mentioned merely by way of example, for any adsorbent material may be used which complies with the condition defined above.

We claim as our invention:

1. The process of obtaining sterols from a fatty substance which has been substantially freed from phosphatid'es and mucilages, which consists in extracting such substantially phospha? tide-free and mucilage-free fatty substance with an organic sterol-dissolving solvent that when cold is substantially immiscible with the oil, separating the solvent and its contained solutes from the oil, and separating sterols from the solvent. t

2. The process of obtaining sterols from a fataaaasvs ty substance, which consists in bringing it in liquid state into intimate contact with an adsorbent of which a 20-gram lot is capable of adsorbing from 200grams of a crude soybean oil of between 0.06% and 0.08% phosphorous content at least enough phosphorous-containing material to reduce the phosphorous content of the oil to one-third its original value, extracting the oilremaining after such adsorption with an organic sterol-dissolving solvent that when cold is substantially immiscible with the oil, separating the solvent and its contained solutes from the oil, and separating sterols from the'solv'ent.

3. The process of obtaining sterols from a fatty substance, which consists in brinaing it in liquid state intointimate contact with an adsorbent of which a 20-gram lot is capable of ad sorbing from 200 grams of a crude soybean oil of between 0.06% and 0.08% phosphorous content at least enough phosphorous-containing material to reduce the phosphorous content of the oil to one-thirdits original value, extracting with acetone the adsorbent material with the adsorbed material thereon, subiectingthe acetone extract to evaporation to leave an oily residue which after filtration is rich in sterols but is substantially free from phosphatides and mucilages and largely free from sterol glucosideaextracting that oily residue with an organic steroldissolving solvent that when cold is substantially immiscible with the oil, separating the solvent and its contained solutes from the oil, and separating sterols from the solvent.

4. The process of obtaining sterols from a fatty substance, which consists in bringing it in liquid state into intimate contact with an adsorbent of which a ZO-gram lot is capable of adsorbing from 200 grams of a crude soybean oil of between 0.06% and 0.08% phosphorous content at least enough phosphorous-containing material to reduce the phosphorous content of the oil to one-third its original value, extracting with acetone the adsorbent material with the adsorbed material thereon, subjecting the acetone extract to evaporation to leave an oily residue which after filtration is rich in sterols but is substantially free from phosphatides and mucilages and largely free from sterol glucosides, so that there are two oil-fractions of which one is the residue from the acetone extract and the other is the filtrate after-treatment with the adsorbent materiaLextracting at least one of those oil-fractions. with an organic sterol-dissolving solvent that when cold issubstantialiy immiscible with, the oil, separating the solvent and its contained solutes from the oil, and separating sterols from the solvent.

5. The process of obtaining sterols from a fatty substance which has been substantially freed from phosphatides and mucilages, which consists in extracting such substantially phosphatide-free and mucilage-free fatty substance with a an organic sterol-dissolving solventthat when cold is substantially immiscible with the oil, septhe sterols, extracting the first fraction with acetone to separate it into two sub-fractions of which the first is an oil which contains the sterols and some of the sterol glucosides of the first fraction but substantially none of the phosphatides and mucilages and the second contains the remainder of the first fraction, extracting one or both of the oils constituting the second fraction and the first sub-fraction of the first fraction with an organic sterol-dissolving solvent which when cold is substantially immiscible with the oil, and separating the sterols from the solvent.

'7. The process of obtaining sterols from a fat ty substance, which consists in separating it by selective adsorption into a portion which contains phosphatides and mucilages and a portion which contains sterols but is substantially free from phosphatides and mucilages, extracting the second portion with an organic sterol-dissolving solvent which when cold is substantially immiscible with the oil, and separating the sterols from the solvent.

HENRY R. KRAYBILL. MAX HORSLEY THORNTON. 

